For dogs, it moves from civil to criminal with circumstances such as what the owner knew about the dog’s behavior, how serious the injury was, whether the owner intentionally or recklessly allowed the dangerous situation, and any prior incidents. Same can easily be applied to AI labs.
At this point though, we know AI can "escape" and do criminal acts it wasn't told to do - therefore, if it happens again (= if the developers allow it to happen again) they (the developers) can be held responsible.